Sink



FIG. 1 is a top plan view of a sink showing our new design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a bottom plan view thereof; and

FIG. 5 is a perspective view taken from the top, front and right side thereof. 

The ornamental design for a sink, as shown. 